Accession No
1749
Brief Description
universal equinoctial ring dial, by Michael Butterfield, French, 1700 (c)
Origin
France; Paris
Maker
Butterfield, Michael
Class
dials
Earliest Date
1700
Latest Date
1700
Inscription Date
Material
metal (silver)
Dimensions
length 112mm; diameter 84mm
Special Collection
Holden-White collection
Provenance
On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum. C. Holden-White collection no. 1935-103.
Inscription
‘Butterfield AParis’
Description Notes
Meridian ring calibrated for Northern latitudes, divided 0 - [90˚], numbered by 10˚, subdivided to 1˚; also a list of towns and latitudes. (Sliding) Suspension shackle with silver suspension ring. Equinoctial ring divided I - XII, I - XII, numbered by I, subdivided to 15 minutes; similarly divided on inner face. Reverse carries list of towns and latitudes. Hinged clips to hold hour ring in position. Pierced bridge with date scale divided to named (initialled) month, subdivided to 5 days; on reverse a zodiac scale divided to sign and subdivided to 5˚ (1st Aries = 20 March). Sliding pinhole gnomon. End of bridge, bridge supports etc. decoratively engraved.
Condition: good.
References
Events
Description
The universal equinoctial ring dial was designed by the English mathematician William Oughtred in the first half of the seventeenth century. It could be used at any latitude, so was a popular timekeeper for sailors and other travellers. It was really a much simplified version of the armillary sphere, only keeping the parts which were needed for telling the time.
The universal equinoctial ring dial consists of two rings and a bridging bar inside the inner ring. The outer ring represents a circle passing through the North and South celestial poles. The inner ring is called the ‘equinoctial’ ring because it represents the celestial equator. The bridging bar represents the axis of the world, just as the gnomon on an ordinary horizontal dial does. So the instrument is a very simple model of the heavens.
01/02/2001
Created by: Dr Hester Higton on 01/02/2001
FM:39997
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